During the first three years of this project (1975-77) extensive, detailed data were collected by four field researchers who studied the demography, economics, warfare patterns and kinship behavior of many widely-separated villages of Amerindians (Yanomamo and Ye'kwana) in southern Venezuela. This data was in large measure coded and analyzed by computer methods during the third year of the project, resulting in a large number of publishable manuscripts. The current year's effort will be devoted to refining these manuscripts for publication and to develop additional publications from yet-unanalyzed data. Most of the publications deal wiih hypotheses that derive from Sociobiological theory, particularly hypotheses that refer to kin selection, inclusive fitness, reciprocal altruism, differential reproductive success and mating systems. Analyses of six-ratio manipulation through infanticide and infant neglect, patterns of support during aggressive encounters, sharing of economic goods and labor and systematic exchanges of marriageable partners between kinship groups are examined in terms of coefficients of genealogical relatedness derived from S. Wright's Inbreeding Coefficient. The extend to which individuals tend to favor close kin versus distant kin in social interactions (Hamilton's inclusive fitness hypothesis) and what this might mean in terms of increasing repoductive success will be subjected to rigorous testing.